+++ /dev/null
-/* MN10300 Kernel probes implementation
- *
- * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
- * Written by Mark Salter (msalter@redhat.com)
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public Licence as published by
- * the Free Software Foundation; either version 2 of the Licence, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public Licence for more details.
- *
- * You should have received a copy of the GNU General Public Licence
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-#include <linux/kprobes.h>
-#include <linux/ptrace.h>
-#include <linux/spinlock.h>
-#include <linux/preempt.h>
-#include <linux/kdebug.h>
-#include <asm/cacheflush.h>
-
-struct kretprobe_blackpoint kretprobe_blacklist[] = { { NULL, NULL } };
-const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
-
-/* kprobe_status settings */
-#define KPROBE_HIT_ACTIVE 0x00000001
-#define KPROBE_HIT_SS 0x00000002
-
-static struct kprobe *cur_kprobe;
-static unsigned long cur_kprobe_orig_pc;
-static unsigned long cur_kprobe_next_pc;
-static int cur_kprobe_ss_flags;
-static unsigned long kprobe_status;
-static kprobe_opcode_t cur_kprobe_ss_buf[MAX_INSN_SIZE + 2];
-static unsigned long cur_kprobe_bp_addr;
-
-DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
-
-
-/* singlestep flag bits */
-#define SINGLESTEP_BRANCH 1
-#define SINGLESTEP_PCREL 2
-
-#define READ_BYTE(p, valp) \
- do { *(u8 *)(valp) = *(u8 *)(p); } while (0)
-
-#define READ_WORD16(p, valp) \
- do { \
- READ_BYTE((p), (valp)); \
- READ_BYTE((u8 *)(p) + 1, (u8 *)(valp) + 1); \
- } while (0)
-
-#define READ_WORD32(p, valp) \
- do { \
- READ_BYTE((p), (valp)); \
- READ_BYTE((u8 *)(p) + 1, (u8 *)(valp) + 1); \
- READ_BYTE((u8 *)(p) + 2, (u8 *)(valp) + 2); \
- READ_BYTE((u8 *)(p) + 3, (u8 *)(valp) + 3); \
- } while (0)
-
-
-static const u8 mn10300_insn_sizes[256] =
-{
- /* 1 2 3 4 5 6 7 8 9 a b c d e f */
- 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, /* 0 */
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 1 */
- 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, /* 2 */
- 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, /* 3 */
- 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, /* 4 */
- 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, /* 5 */
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6 */
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 7 */
- 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 8 */
- 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 9 */
- 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* a */
- 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* b */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 2, /* c */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* d */
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* e */
- 0, 2, 2, 2, 2, 2, 2, 4, 0, 3, 0, 4, 0, 6, 7, 1 /* f */
-};
-
-#define LT (1 << 0)
-#define GT (1 << 1)
-#define GE (1 << 2)
-#define LE (1 << 3)
-#define CS (1 << 4)
-#define HI (1 << 5)
-#define CC (1 << 6)
-#define LS (1 << 7)
-#define EQ (1 << 8)
-#define NE (1 << 9)
-#define RA (1 << 10)
-#define VC (1 << 11)
-#define VS (1 << 12)
-#define NC (1 << 13)
-#define NS (1 << 14)
-
-static const u16 cond_table[] = {
- /* V C N Z */
- /* 0 0 0 0 */ (NE | NC | CC | VC | GE | GT | HI),
- /* 0 0 0 1 */ (EQ | NC | CC | VC | GE | LE | LS),
- /* 0 0 1 0 */ (NE | NS | CC | VC | LT | LE | HI),
- /* 0 0 1 1 */ (EQ | NS | CC | VC | LT | LE | LS),
- /* 0 1 0 0 */ (NE | NC | CS | VC | GE | GT | LS),
- /* 0 1 0 1 */ (EQ | NC | CS | VC | GE | LE | LS),
- /* 0 1 1 0 */ (NE | NS | CS | VC | LT | LE | LS),
- /* 0 1 1 1 */ (EQ | NS | CS | VC | LT | LE | LS),
- /* 1 0 0 0 */ (NE | NC | CC | VS | LT | LE | HI),
- /* 1 0 0 1 */ (EQ | NC | CC | VS | LT | LE | LS),
- /* 1 0 1 0 */ (NE | NS | CC | VS | GE | GT | HI),
- /* 1 0 1 1 */ (EQ | NS | CC | VS | GE | LE | LS),
- /* 1 1 0 0 */ (NE | NC | CS | VS | LT | LE | LS),
- /* 1 1 0 1 */ (EQ | NC | CS | VS | LT | LE | LS),
- /* 1 1 1 0 */ (NE | NS | CS | VS | GE | GT | LS),
- /* 1 1 1 1 */ (EQ | NS | CS | VS | GE | LE | LS),
-};
-
-/*
- * Calculate what the PC will be after executing next instruction
- */
-static unsigned find_nextpc(struct pt_regs *regs, int *flags)
-{
- unsigned size;
- s8 x8;
- s16 x16;
- s32 x32;
- u8 opc, *pc, *sp, *next;
-
- next = 0;
- *flags = SINGLESTEP_PCREL;
-
- pc = (u8 *) regs->pc;
- sp = (u8 *) (regs + 1);
- opc = *pc;
-
- size = mn10300_insn_sizes[opc];
- if (size > 0) {
- next = pc + size;
- } else {
- switch (opc) {
- /* Bxx (d8,PC) */
- case 0xc0 ... 0xca:
- x8 = 2;
- if (cond_table[regs->epsw & 0xf] & (1 << (opc & 0xf)))
- x8 = (s8)pc[1];
- next = pc + x8;
- *flags |= SINGLESTEP_BRANCH;
- break;
-
- /* JMP (d16,PC) or CALL (d16,PC) */
- case 0xcc:
- case 0xcd:
- READ_WORD16(pc + 1, &x16);
- next = pc + x16;
- *flags |= SINGLESTEP_BRANCH;
- break;
-
- /* JMP (d32,PC) or CALL (d32,PC) */
- case 0xdc:
- case 0xdd:
- READ_WORD32(pc + 1, &x32);
- next = pc + x32;
- *flags |= SINGLESTEP_BRANCH;
- break;
-
- /* RETF */
- case 0xde:
- next = (u8 *)regs->mdr;
- *flags &= ~SINGLESTEP_PCREL;
- *flags |= SINGLESTEP_BRANCH;
- break;
-
- /* RET */
- case 0xdf:
- sp += pc[2];
- READ_WORD32(sp, &x32);
- next = (u8 *)x32;
- *flags &= ~SINGLESTEP_PCREL;
- *flags |= SINGLESTEP_BRANCH;
- break;
-
- case 0xf0:
- next = pc + 2;
- opc = pc[1];
- if (opc >= 0xf0 && opc <= 0xf7) {
- /* JMP (An) / CALLS (An) */
- switch (opc & 3) {
- case 0:
- next = (u8 *)regs->a0;
- break;
- case 1:
- next = (u8 *)regs->a1;
- break;
- case 2:
- next = (u8 *)regs->a2;
- break;
- case 3:
- next = (u8 *)regs->a3;
- break;
- }
- *flags &= ~SINGLESTEP_PCREL;
- *flags |= SINGLESTEP_BRANCH;
- } else if (opc == 0xfc) {
- /* RETS */
- READ_WORD32(sp, &x32);
- next = (u8 *)x32;
- *flags &= ~SINGLESTEP_PCREL;
- *flags |= SINGLESTEP_BRANCH;
- } else if (opc == 0xfd) {
- /* RTI */
- READ_WORD32(sp + 4, &x32);
- next = (u8 *)x32;
- *flags &= ~SINGLESTEP_PCREL;
- *flags |= SINGLESTEP_BRANCH;
- }
- break;
-
- /* potential 3-byte conditional branches */
- case 0xf8:
- next = pc + 3;
- opc = pc[1];
- if (opc >= 0xe8 && opc <= 0xeb &&
- (cond_table[regs->epsw & 0xf] &
- (1 << ((opc & 0xf) + 3)))
- ) {
- READ_BYTE(pc+2, &x8);
- next = pc + x8;
- *flags |= SINGLESTEP_BRANCH;
- }
- break;
-
- case 0xfa:
- if (pc[1] == 0xff) {
- /* CALLS (d16,PC) */
- READ_WORD16(pc + 2, &x16);
- next = pc + x16;
- } else
- next = pc + 4;
- *flags |= SINGLESTEP_BRANCH;
- break;
-
- case 0xfc:
- x32 = 6;
- if (pc[1] == 0xff) {
- /* CALLS (d32,PC) */
- READ_WORD32(pc + 2, &x32);
- }
- next = pc + x32;
- *flags |= SINGLESTEP_BRANCH;
- break;
- /* LXX (d8,PC) */
- /* SETLB - loads the next four bytes into the LIR reg */
- case 0xd0 ... 0xda:
- case 0xdb:
- panic("Can't singlestep Lxx/SETLB\n");
- break;
- }
- }
- return (unsigned)next;
-
-}
-
-/*
- * set up out of place singlestep of some branching instructions
- */
-static unsigned __kprobes singlestep_branch_setup(struct pt_regs *regs)
-{
- u8 opc, *pc, *sp, *next;
-
- next = NULL;
- pc = (u8 *) regs->pc;
- sp = (u8 *) (regs + 1);
-
- switch (pc[0]) {
- case 0xc0 ... 0xca: /* Bxx (d8,PC) */
- case 0xcc: /* JMP (d16,PC) */
- case 0xdc: /* JMP (d32,PC) */
- case 0xf8: /* Bxx (d8,PC) 3-byte version */
- /* don't really need to do anything except cause trap */
- next = pc;
- break;
-
- case 0xcd: /* CALL (d16,PC) */
- pc[1] = 5;
- pc[2] = 0;
- next = pc + 5;
- break;
-
- case 0xdd: /* CALL (d32,PC) */
- pc[1] = 7;
- pc[2] = 0;
- pc[3] = 0;
- pc[4] = 0;
- next = pc + 7;
- break;
-
- case 0xde: /* RETF */
- next = pc + 3;
- regs->mdr = (unsigned) next;
- break;
-
- case 0xdf: /* RET */
- sp += pc[2];
- next = pc + 3;
- *(unsigned *)sp = (unsigned) next;
- break;
-
- case 0xf0:
- next = pc + 2;
- opc = pc[1];
- if (opc >= 0xf0 && opc <= 0xf3) {
- /* CALLS (An) */
- /* use CALLS (d16,PC) to avoid mucking with An */
- pc[0] = 0xfa;
- pc[1] = 0xff;
- pc[2] = 4;
- pc[3] = 0;
- next = pc + 4;
- } else if (opc >= 0xf4 && opc <= 0xf7) {
- /* JMP (An) */
- next = pc;
- } else if (opc == 0xfc) {
- /* RETS */
- next = pc + 2;
- *(unsigned *) sp = (unsigned) next;
- } else if (opc == 0xfd) {
- /* RTI */
- next = pc + 2;
- *(unsigned *)(sp + 4) = (unsigned) next;
- }
- break;
-
- case 0xfa: /* CALLS (d16,PC) */
- pc[2] = 4;
- pc[3] = 0;
- next = pc + 4;
- break;
-
- case 0xfc: /* CALLS (d32,PC) */
- pc[2] = 6;
- pc[3] = 0;
- pc[4] = 0;
- pc[5] = 0;
- next = pc + 6;
- break;
-
- case 0xd0 ... 0xda: /* LXX (d8,PC) */
- case 0xdb: /* SETLB */
- panic("Can't singlestep Lxx/SETLB\n");
- }
-
- return (unsigned) next;
-}
-
-int __kprobes arch_prepare_kprobe(struct kprobe *p)
-{
- return 0;
-}
-
-void __kprobes arch_copy_kprobe(struct kprobe *p)
-{
- memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);
-}
-
-void __kprobes arch_arm_kprobe(struct kprobe *p)
-{
- *p->addr = BREAKPOINT_INSTRUCTION;
- flush_icache_range((unsigned long) p->addr,
- (unsigned long) p->addr + sizeof(kprobe_opcode_t));
-}
-
-void __kprobes arch_disarm_kprobe(struct kprobe *p)
-{
-#ifndef CONFIG_MN10300_CACHE_SNOOP
- mn10300_dcache_flush();
- mn10300_icache_inv();
-#endif
-}
-
-void arch_remove_kprobe(struct kprobe *p)
-{
-}
-
-static inline
-void __kprobes disarm_kprobe(struct kprobe *p, struct pt_regs *regs)
-{
- *p->addr = p->opcode;
- regs->pc = (unsigned long) p->addr;
-#ifndef CONFIG_MN10300_CACHE_SNOOP
- mn10300_dcache_flush();
- mn10300_icache_inv();
-#endif
-}
-
-static inline
-void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
-{
- unsigned long nextpc;
-
- cur_kprobe_orig_pc = regs->pc;
- memcpy(cur_kprobe_ss_buf, &p->ainsn.insn[0], MAX_INSN_SIZE);
- regs->pc = (unsigned long) cur_kprobe_ss_buf;
-
- nextpc = find_nextpc(regs, &cur_kprobe_ss_flags);
- if (cur_kprobe_ss_flags & SINGLESTEP_PCREL)
- cur_kprobe_next_pc = cur_kprobe_orig_pc + (nextpc - regs->pc);
- else
- cur_kprobe_next_pc = nextpc;
-
- /* branching instructions need special handling */
- if (cur_kprobe_ss_flags & SINGLESTEP_BRANCH)
- nextpc = singlestep_branch_setup(regs);
-
- cur_kprobe_bp_addr = nextpc;
-
- *(u8 *) nextpc = BREAKPOINT_INSTRUCTION;
- mn10300_dcache_flush_range2((unsigned) cur_kprobe_ss_buf,
- sizeof(cur_kprobe_ss_buf));
- mn10300_icache_inv();
-}
-
-static inline int __kprobes kprobe_handler(struct pt_regs *regs)
-{
- struct kprobe *p;
- int ret = 0;
- unsigned int *addr = (unsigned int *) regs->pc;
-
- /* We're in an interrupt, but this is clear and BUG()-safe. */
- preempt_disable();
-
- /* Check we're not actually recursing */
- if (kprobe_running()) {
- /* We *are* holding lock here, so this is safe.
- Disarm the probe we just hit, and ignore it. */
- p = get_kprobe(addr);
- if (p) {
- disarm_kprobe(p, regs);
- ret = 1;
- } else {
- p = cur_kprobe;
- if (p->break_handler && p->break_handler(p, regs))
- goto ss_probe;
- }
- /* If it's not ours, can't be delete race, (we hold lock). */
- goto no_kprobe;
- }
-
- p = get_kprobe(addr);
- if (!p) {
- if (*addr != BREAKPOINT_INSTRUCTION) {
- /* The breakpoint instruction was removed right after
- * we hit it. Another cpu has removed either a
- * probepoint or a debugger breakpoint at this address.
- * In either case, no further handling of this
- * interrupt is appropriate.
- */
- ret = 1;
- }
- /* Not one of ours: let kernel handle it */
- goto no_kprobe;
- }
-
- kprobe_status = KPROBE_HIT_ACTIVE;
- cur_kprobe = p;
- if (p->pre_handler(p, regs)) {
- /* handler has already set things up, so skip ss setup */
- return 1;
- }
-
-ss_probe:
- prepare_singlestep(p, regs);
- kprobe_status = KPROBE_HIT_SS;
- return 1;
-
-no_kprobe:
- preempt_enable_no_resched();
- return ret;
-}
-
-/*
- * Called after single-stepping. p->addr is the address of the
- * instruction whose first byte has been replaced by the "breakpoint"
- * instruction. To avoid the SMP problems that can occur when we
- * temporarily put back the original opcode to single-step, we
- * single-stepped a copy of the instruction. The address of this
- * copy is p->ainsn.insn.
- */
-static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
-{
- /* we may need to fixup regs/stack after singlestepping a call insn */
- if (cur_kprobe_ss_flags & SINGLESTEP_BRANCH) {
- regs->pc = cur_kprobe_orig_pc;
- switch (p->ainsn.insn[0]) {
- case 0xcd: /* CALL (d16,PC) */
- *(unsigned *) regs->sp = regs->mdr = regs->pc + 5;
- break;
- case 0xdd: /* CALL (d32,PC) */
- /* fixup mdr and return address on stack */
- *(unsigned *) regs->sp = regs->mdr = regs->pc + 7;
- break;
- case 0xf0:
- if (p->ainsn.insn[1] >= 0xf0 &&
- p->ainsn.insn[1] <= 0xf3) {
- /* CALLS (An) */
- /* fixup MDR and return address on stack */
- regs->mdr = regs->pc + 2;
- *(unsigned *) regs->sp = regs->mdr;
- }
- break;
-
- case 0xfa: /* CALLS (d16,PC) */
- /* fixup MDR and return address on stack */
- *(unsigned *) regs->sp = regs->mdr = regs->pc + 4;
- break;
-
- case 0xfc: /* CALLS (d32,PC) */
- /* fixup MDR and return address on stack */
- *(unsigned *) regs->sp = regs->mdr = regs->pc + 6;
- break;
- }
- }
-
- regs->pc = cur_kprobe_next_pc;
- cur_kprobe_bp_addr = 0;
-}
-
-static inline int __kprobes post_kprobe_handler(struct pt_regs *regs)
-{
- if (!kprobe_running())
- return 0;
-
- if (cur_kprobe->post_handler)
- cur_kprobe->post_handler(cur_kprobe, regs, 0);
-
- resume_execution(cur_kprobe, regs);
- reset_current_kprobe();
- preempt_enable_no_resched();
- return 1;
-}
-
-/* Interrupts disabled, kprobe_lock held. */
-static inline
-int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
-{
- if (cur_kprobe->fault_handler &&
- cur_kprobe->fault_handler(cur_kprobe, regs, trapnr))
- return 1;
-
- if (kprobe_status & KPROBE_HIT_SS) {
- resume_execution(cur_kprobe, regs);
- reset_current_kprobe();
- preempt_enable_no_resched();
- }
- return 0;
-}
-
-/*
- * Wrapper routine to for handling exceptions.
- */
-int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
- unsigned long val, void *data)
-{
- struct die_args *args = data;
-
- switch (val) {
- case DIE_BREAKPOINT:
- if (cur_kprobe_bp_addr != args->regs->pc) {
- if (kprobe_handler(args->regs))
- return NOTIFY_STOP;
- } else {
- if (post_kprobe_handler(args->regs))
- return NOTIFY_STOP;
- }
- break;
- case DIE_GPF:
- if (kprobe_running() &&
- kprobe_fault_handler(args->regs, args->trapnr))
- return NOTIFY_STOP;
- break;
- default:
- break;
- }
- return NOTIFY_DONE;
-}
-
-/* Jprobes support. */
-static struct pt_regs jprobe_saved_regs;
-static struct pt_regs *jprobe_saved_regs_location;
-static kprobe_opcode_t jprobe_saved_stack[MAX_STACK_SIZE];
-
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
-
- jprobe_saved_regs_location = regs;
- memcpy(&jprobe_saved_regs, regs, sizeof(struct pt_regs));
-
- /* Save a whole stack frame, this gets arguments
- * pushed onto the stack after using up all the
- * arg registers.
- */
- memcpy(&jprobe_saved_stack, regs + 1, sizeof(jprobe_saved_stack));
-
- /* setup return addr to the jprobe handler routine */
- regs->pc = (unsigned long) jp->entry;
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- void *orig_sp = jprobe_saved_regs_location + 1;
-
- preempt_enable_no_resched();
- asm volatile(" mov %0,sp\n"
- ".globl jprobe_return_bp_addr\n"
- "jprobe_return_bp_addr:\n\t"
- " .byte 0xff\n"
- : : "d" (orig_sp));
-}
-
-extern void jprobe_return_bp_addr(void);
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- u8 *addr = (u8 *) regs->pc;
-
- if (addr == (u8 *) jprobe_return_bp_addr) {
- if (jprobe_saved_regs_location != regs) {
- printk(KERN_ERR"JPROBE:"
- " Current regs (%p) does not match saved regs"
- " (%p).\n",
- regs, jprobe_saved_regs_location);
- BUG();
- }
-
- /* Restore old register state.
- */
- memcpy(regs, &jprobe_saved_regs, sizeof(struct pt_regs));
-
- memcpy(regs + 1, &jprobe_saved_stack,
- sizeof(jprobe_saved_stack));
- return 1;
- }
- return 0;
-}
-
-int __init arch_init_kprobes(void)
-{
- return 0;
-}
git.samba.org / sfrench / cifs-2.6.git / blobdiff